Hominid Brain Space

I Want More


6 million years ago
Australopithecus
Human ancestor cos it walked upright like us
Small brain and projecting nose
Brain size approx 450cc

2.3 million years ago
Homo Hablis. Handy man
Used stone tools
Larger brain and small projection of nose
Brain size approx 600cc

1.8 million years ago
Homo Erectus
Our true human ancestor. First human-like characteristics
Big brain. Game hunter
Brain size approx 900cc

Today
Homo Sapiens
Us
Bigger brain. Hunts everything
Brain size approx 1400cc

Our brains compose around 2% of our body weight but use around 25% of energy consumed. The brain mostly runs on glucose. Our muscles can burn glucose (blood sugar) or fat for fuel. Brains cannot, as fat particles are too big to cross the blood brain barrier. How come? For the answer we need to look to the past.
For millions of years, our distant ancestors, think arboreal apes, consumed fruits, leaves, shoots, which provide sugar for the brain. Our brains thrived on glucose sugar fuel. As our species evolved, they climbed down from the trees, moved away from fruits, leaves, shoots as the mainstay of their diet and began scavenging and hunting on the savannah, for meat and fats.
Watching the video "Did Cooking Make Make Us Human" on YouTube at 52:30 into the video, Dr Susan Francis runs a test measuring the response of the human brain to the consumption of fat. With 5% fat consumption, there's a small response. With 10% fat consumption, an increased response. At 30% fat consumption, brain centers leap to respond.
Followed by the tut-tuts of: "You know that's not allowed. You know how bad fats are for you. They clog the arteries and cause heart disease". Err what? I thought we had passed that pseudo-science nonsense some time ago. Are we still stuck there with this outmoded view? I need to pick this up in a future blog-post.
Our ancestors survived by switching to a fat and meat diet. There were no vegi take-outs, vegi restaurants or smoothie bars. Fruit trees only bear fruit for a short time once a year. What did our vegi-ancestors eat the other 10 months of the year? Wheat, maize, rice and other grain crops were discovered around 10,000 years ago, so they came 5,990,000 years too late to maintain our vegetarian diet. Guess that only leaves one option: a meat/fat diet.
Our ancestors were meat eaters, including animal fats. They were scavengers or hunters, much like many modern-day indigenous hunter / gatherer tribes, such as the San of Botswana, the Kombai of Papua New Guinea, tribes living in the Amazon rain forest or the Inuit living in North West Canada. These tribes live by killing animals and consuming their fat and flesh.
But the tut-tuts of Dr Susan Francis are misplaced. Sure fat consumption lights up the pleasure centers of the brain, cos fat consumption is desirable. You cannot survive without fat in your diet.
The annoying part of the experiment, was they did not measure the sugar response on the human brain. I'm not a gambling man, but I'll wager the brain lights up like an Xmas tree when high levels of sugar or carbohydrates are consumed.
More to come.